Liquefaction of gases.



:Toall wkom it may concern?" i -zen of the Republic of 139,753, filedJan. 2 I the point of view of the frigorific e'tficiency, .theimportance has been set forth of raising renoaens CLAUDE, or rAnIsrnAncn, nssrexoa r socrn'rfi "Tznam trauma (socrErE ANONYME rounn'n'rnnn Er LnxrIlorra'rrons DES PROGEDES cnonens CLAUDE),

min'istrateur de.la Socit LAir Liquide (St. Anonyme pour lEtude etlExploitation des Procds Georges Claude) a citi- France, and resident of43 Rue St. Lazare, Paris, France, have invented Improvements in the-Liquefac-- tion of Gases,

of whieh'the following is a description.

the process described-in an application for Letters Patent of the UnitedStates, Serial No.

, as much as possible the temperature at which fying a portion ofthe airwhich is expan ed, 1 the course has been the expansion with externalwork 'of the compressed air-takes placein' liquid air ma-' chines.With'th1s object, instead of H ueadopted of utilizing I its coolingeffect for causing the liquefaction of .a .idistmct portion of "air;this latter,

air itsel and, conseell'ect the expansion of the compressedair inseveral stages, each partial expansion being followed, r as indicated'above, by the liquefaction (owing to the low temperature of thepartially expanded air) of a distinct ;portion of 'com- "pressed air;the partially expanded air thus plying the liquefier or liquefiersemployed "in the process with prgyiously "cooled combecomes re-heatedand capable of accom-. 40

plishing its following partial expansion under more favorableconditions.

' According to-the present invention the two methods above indicated:are utilized with new conditions which constitute ayconsiderableimprovement in the 'same direction. This improvement is obtained bysuppressed oxygen, its pressure being prefer ably adjacent to thecritical pressure, say

has par-f liquid air which will be obtained 1903 in which, from;

. ntended to serve as mentary supplyfor apparatus for extractcompressedand cold by reason of its pressure, liquefies at a much higher temerature than could the expanded of the apparatus,

the working sucked by the compressor or n renoua "tieunrncrroxfor GASES.

I Patented working temperatures may be established Be it known that I,GEORGES CLAUDE, ad

at about 20 C, above those which would must when .air is used intheliquefier and this difference in temperature is very large at thesetemperatures which are comparativelyclose to the absolute zero, particu-1arl-y,.if ,the imperfection of the gaseous state-of compressed air atthese temperatures be taken'into account. It will therev fore be seenthat the employment This invention relates to the li uefaction .ofatmospheric and other gases and ticular reference to I the specificationof of compressed oxygen constitutes a great 1m ovement in regard to theworking temperatures. Obviously it is liquid oxygen and not under theseconditions. 7 v. p

In cases in which the liquid obtained is a reserve or supplemg oxygenfrom air instead of the liquid air generally used for this purpose, theprocess may be applied in the following manner: At the beginning of theoperation, that is to say before the oxygen apparatus has'gge'en startedthe liquefier' or liquefiers may" be supplied with a part of the supplycircuit or with compressed air drawn from another source inconformitywith the process set forth in the specification of the aforesaidapplication Serial No. 139,753. It is also pressedoxygen farising. froma preceding operation for example. As soon as the apparatus is started,and oxygen gas liberated,

a portion of said'gas, after its coldness has been utilized, iscompressed by means of an auxiliary compressor which may for example beactuated by power derived from the work due to expansion; the compressedgas is then sent into the liquefier or liquefiers,

after having been cooled by its passage through temperature exchangerswhich are traversed in the opposite direction either by a'portion of theexpanded air ofthe apparatus, of the separator apparatus. A convenientmethod is to utilize a special exchanger traversed on the one hand bythe oxygen and on the other hand by the compressed in this manner, theregulation is automatic. In proportion as it is produced, the liquidoxygen is decanted into the vaporizer vessel of the separator apparatus;it is not necessary to take into account the oxygen inor by aportion ofthe vaporized gases oxygen produced possible to employ comand,consequently,

ing under better conditions.

' The accompanying drawing represents by way of example an arrangementof apparatus for carrying the invention into practice.

This arrangement exchanger A, where the compressed air and the expandedair circulate in opposite directions, of the exchanger L to whichcompressed oxygen is supplied and in which the expanded air circulateslikewise in the reverse direction, of the liquefier E C and of theexpansion machine B D. The com-' pressed oxygen enters the exchanger Lat 8, the nest of tubes of the exchanger;

traverses which it leaves cooled through the pipe 9, the latterconducting it into the nest of tubes of the liquefier E 0 through whichit passes in the downward direction, and where it becomes liquefied. Theliquid oxyen may be drawn out of the applaratus' the cock G, orconducted t rough the cock H and the pipe J to the separator apparatus,where it serves as reserve or supplementary liquid. On the other hand,the compressed air enters the exchanger A at I, passes throu changer,which it leaves cooled through the through pipe 2 the latter conductingit to the first expansion cylinder B of the expansion machine B D whereit is subjectto a partial expansion. The cooled expanded air is-conducted through the pipe 3 into the upper part 0 of the liquefier EC, which it traverses in theupward direction in liquefying thecompressed and cold oxygen contained in the nest of tubes; reheatedowing to this liquefaction theair then proceeds through the pipe 4: tothe second cylinder D of the machine, there it is expanded completelyand consequently cooled, from there the pipe 5 conducts it into thelower part E of the liquefier E C, after having caused in E theliquefaction of the compressed oxygen in the nest of tubes, the expandedair leaves the liquefier by the pipe 6; the cock K enables a portion ofit to be conducted through the pipe 6 into the oxygen exchanger L, whereit'cools the compressed oxygen before its ad- 'mission to the liquefier,the air escaping finally into the atmosphere through the pipe 10;theotherportion of the expanded air, which is the most importantportion, passes consists broadly of the;

. ature,

gh the nest of" tubes in-this ex-.

through the pipe 6 into the principal ex-- changer A where it cools thecompressed air to'be expanded, and finally escapes int-o the atmospherethrough the 1pc a If it is desired to emp 0y nltrogen as expansion as,it will traverse the circuit 1, A,

2, B, 3, 4, D, 5, E, 6, A, 7, previously indicatedfor the compresseda1r.

V The reasons. for employing oxygen for improving the conditions ofliquefaction likewise hold good for its employment in expansion withoutexternal work. It is indeed known that this method of expansion isexclusively based upon theperformance of internal work due to the factthat at the initial temperature of the cycle the gas in question isnotfa perfect gas. Now 1n the case of oxygen all other things beingequal, this imper ection is far more accentuated than in the case ofair,-"so that the efliciency of the liquefying apparatus will be largelyincreased if it be supplied with oxygen.

It is obvious that this method which consists in supplying the liquefieror liquefiers with a compressed gaswhich is different from that which isexpanded, and presenting relatively to the latter a higher criticaltemperature, might present the same advantages in other analogous cases,for example, in the case ofwater gas.

Claims:

1. The method of liquefying permanent gases which consists in subjectinga compressed and cooled permanent gas to the indirect cooling action ofanother expanded permanent gas witha lower critical temperthe remainingcold of which after being utilized for liquefying purpose is used incooling both compressed permanent gases the one to be liquefied and theother to be expanded.

2. The method of liquefying permanent gases which consists incompressing and cooling the permanent gas to be liquefied and arefrigerating permanent gas whose critical temperature is lower thanthat of the gas to be liquefied, subjecting the compressed gas with thehigher critical temperature to the indirect cooling action of the gaswith the lower critical temperature which is itself cooled by successiveexpansions, the cooling action taking place after each expansion and theremain'in cold of which after being utilized for llquefying purpose isused in cooling both compressed permanent gases the one to be liquefiedand the other to be expanded.

. 3. The method of liquefying oxygen gas which consists in subjectingcompressed and cooled oxygen gas to the indirect cooling action ofexpanded'gaseous air, the remaining 1 which consists in compressing andcool' apart oxygen gas and air, subjecting the compressed oxygen to theindirect action of the gaseous air which is itself cooled by successlveexpansions, the cooling action taking place after each expansion andusing the remaining cold of the expandedair to cool the compressedoxygen and the compressed air.

5. The method of liquefying oxygen gas which consists in compressing andcooling apart oxygen gas and air, allowing the air to partially expandwith production of external work, transmitting the cold of thispartiallyexpanded air to the cooled compressed oxygen, further expanding the airwith production of external work and subjecting the cooled compressedoxygen to the cooling action of this finally expanded air and furtherutilizing the remaining cold of this expanded air to cool both thecompressed oxygen gas and the compressed air, substantially as setforth.

In testimony whereof I afiix my signature in presence of two Witnesses.

, GEORGES CLAUDE. Witnesses:

ANDRE HEIBRONNER, H. C. Coxn.

